To compensate for the loss of a steel roof, which braces the body, the chassis has been massively reinforced, pushing up costs as well as weight. Mercedes adds nearly 300lb of metal to ensure that the cabriolet does not dither like a jelly on rough roads.
The 100lb multi-layer hood - a marvel of mechanical engineering with six hydraulic cylinders and 34 joints in its complex frame - is said to be good for 20,000 trouble-free operations. Lowering it is simple but not fully automatic, as you have to release a couple of nail-threatening levers first.
With the top up, wind noise is remarkably low for a convertible. Rear- three-quarter visibility is seriously impaired as there are no quarter- lights to supplement the heatable glass rear window. Even when open to the elements, the cabin is cosy.
Mercedes' new 24-valve twin-cam 3.2-litre engine is smooth and vigorous. The six-cylinder engine and five-speed automatic transmission (costing pounds 726 more than the standard four-speeder) work in seamless harmony, surging strongly when you sink the heavy accelerator. There is little or no gain in performance with five gears but cruise economy is marginally better. Whatever the transmission, consumption is quite heavy.
To drive a Mercedes of this calibre is to be pampered by design indulgence - and irritated by unexpected shortcomings, such as board-like seats that feel too firm.
Audi 2.3 cabriolet pounds 22,199. Coupe-based four-seater with neat, well engineered three-layer hood that is easy to raise and lower manually. Cosy with top up, chassis rigidity good. Leisurely performance from 2.3-litre engine.
BMW 3-series convertible, pounds 19,245. Available only with 1.8 four-cylinder engine, so performance modest. Nice to drive. Headgear mars car's lines and is not as easy to work as Audi's.
Ferrari Mondial cabriolet, pounds 72,000. Mid-engined four-seater sports-tourer with dazzling performance, terrific handling
Jaguar XJS 4.0 convertible, pounds 39,264. Huge and space- inefficient; more charm, character and luxury than go: performance of 4.0 six-cylinder engine no better than the Mercedes' 3.2.
Porsche 968 cabriolet, pounds 37,175. Lots more fun than Merc, but only two proper seats. Fast, civilised 944-based thoroughbred. Fine handling, grip and performance.
Mercedes-Benz 320CE cabriolet, pounds 45,100 before extras ( pounds 51,840 as tested). Engine: 3,199cc, six cylinders, 24 valves, 220bhp at 5,500rpm. Transmission: five-speed automatic gearbox (four-speeder standard), rear-wheel drive. Performance: top speed 140mph, 0-60mph in 8.0 seconds, fuel consumption 19-26mpg average.Reuse content